/* Serial driver */

/* Copyright (C) 2009-2011 David Zanetti
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */


#include <avr/io.h>
#include <avr/pgmspace.h>
#include <stdio.h>
#include <avr/eeprom.h>
#include <avr/interrupt.h>
#include <util/atomic.h>
#include <stdlib.h>

#include "serial.h"

#include "global.h"
#include <util/delay.h>

#include "ringbuffer.h"

#define RUN_USART0_TX UCSR0B |= (1 << UDRIE0); 
#define RUN_USART1_TX UCSR1B |= (1 << UDRIE1); 

/* ring buffers */
char usart0_txring[256];
char usart0_rxring[32];
uint8_t usart0_tx_wp, usart0_rx_wp, usart0_tx_rp, usart0_rx_rp;
char usart1_txring[64];
char usart1_rxring[64];
uint8_t usart1_tx_wp, usart1_rx_wp, usart1_tx_rp, usart1_rx_rp;

#define RMASK0T 0xff
#define RMASK0R 0x1f

#define RMASK1 0x3f
#define RMASK1R 0x3f
#define RMASK1T 0x1f

/* interrupt handler for packets on TX USART0 */
ISR(USART0_UDRE_vect) {
        /* check to see if we have anything to send */
        if (!ring_readable_unsafe(usart0_tx_rp, usart0_tx_wp, RMASK0T)) {
                /* disable the interrupt and then exit, nothing more to do */
                UCSR0B &= ~(1 << UDRIE0);
                return;
        }
        /* TX the waiting packet */
        UDR0 = ring_read_unsafe(usart0_txring, &usart0_tx_rp, RMASK0T);
        return;
}

/* this handles packets coming into the serial port */
ISR(USART0_RX_vect) {
        char s;

        s = UDR0;

        ring_write_force_unsafe(usart0_rxring, &usart0_rx_rp, &usart0_rx_wp, RMASK0R,
                        s);
#if defined(USART0_ECHO)
        ring_write_force_unsafe(usart0_txring, &usart0_tx_rp, &usart0_tx_wp, RMASK0T,
                        s);
        UCSR0B |= (1 << UDRIE0); /* and make sure we're writing this out */
#endif

        flag_serial |= FLAG_SERIAL_U0_RX; /* indicate to main loops we had an RX */

#if defined(USART0_IS_CONSOLE)
        if (s == '\r') {
                flag_serial |= FLAG_SERIAL_U0_CMD; /* and we got a completed command */
        }
#endif
}

/* interrupt handler for packets on TX USART1 */
ISR(USART1_UDRE_vect) {
        /* check to see if we have anything to send */
        if (!ring_readable_unsafe(usart1_tx_rp, usart1_tx_wp, RMASK1T)) {
                /* disable the interrupt and then exit, nothing more to do */
                UCSR1B &= ~(1 << UDRIE1);
                return;
        }
        /* TX the waiting packet */
        UDR1 = ring_read_unsafe(usart1_txring, &usart1_tx_rp, RMASK1T);
        return;
}

/* this handles packets coming into the serial port */
ISR(USART1_RX_vect) {
        char s = 0;

        s = UDR1;

        ring_write_force_unsafe(usart1_rxring, &usart1_rx_rp, &usart1_rx_wp, RMASK1R,
                        s);
#if defined(USART1_ECHO)
        ring_write_force_unsafe(usart1_txring, &usart1_tx_rp, &usart1_tx_wp, RMASK0T,
                        s);
        UCSR1B |= (1 << UDRIE1); /* and make sure we're writing this out */
#endif

        flag_serial |= FLAG_SERIAL_U1_RX; /* indicate to main loops we had an RX */

#if defined(USART1_IS_CONSOLE)
        if (s == '\r') {
                flag_serial |= FLAG_SERIAL_U1_CMD; /* and we got a completed command */
        }
#endif
}

void serial0_init(uint16_t baud) {
        uint16_t ubrr;

        /* init ringbuffer pointers */
        usart0_tx_wp = 0;
        usart0_rx_wp = 0;
        usart0_tx_rp = 0;
        usart0_rx_rp = 0;

        /* now calculate baud rat */
        UCSR0A |= (1 << U2X0);
        ubrr = ((F_CPU / (baud*8UL))-1);
        UBRR0H = (ubrr >> 8);
        UBRR0L = (ubrr & 0xff);

        /* enable TX, RX, RX Interrupt */
        UCSR0B |= (1 << RXEN0) | (1 << TXEN0) | (1 << RXCIE0);
}

void serial1_init(uint16_t baud) {
        uint16_t ubrr;

        usart1_tx_wp = 0;
        usart1_rx_wp = 0;
        usart1_tx_rp = 0;
        usart1_rx_rp = 0;

        /* now calculate baud rat */
        UCSR1A |= (1 << U2X1);
        ubrr = ((F_CPU/(baud*8UL))-1);
        UBRR1H = (ubrr >> 8);
        UBRR1L = (ubrr & 0xff);

        /* eanble TX/RX */
        UCSR1B |= (1 << RXEN1) | (1 << TXEN1) | (1 << RXCIE1);

}

uint8_t serial0_tx_cout(char s) {
        if (!ring_writeable(usart0_tx_rp, usart0_tx_wp, RMASK0T)) {
                return 0;
        }
        ring_write(usart0_txring,&usart0_tx_wp, RMASK0T, s);

        RUN_USART0_TX;

        return 1;
}

uint8_t serial1_tx_cout(char s) {
        if (!ring_writeable(usart1_tx_rp, usart1_tx_wp, RMASK1)) {
                return 0;
        }
        ring_write(usart1_txring,&usart1_tx_wp, RMASK1, s);

        RUN_USART1_TX;

        return 1;
}

uint8_t serial0_tx(const char *str, uint8_t len) {
        /* loop over each char in the buffer */
        while (len) {
                /* buiffer isn't full */
                if (!ring_writeable(usart0_tx_rp, usart0_tx_wp, RMASK0T)) {
                        return 0;
                }
                /* write char */
                ring_write(usart0_txring,&usart0_tx_wp, RMASK0T, *str++);
                /* move on */
                len--;
        }

        RUN_USART0_TX;

        return 1;
}

uint8_t serial1_tx(const char *str, uint8_t len) {
        /* loop over each char in the buffer */
        while (len) {
                /* buiffer isn't full */
                if (!ring_writeable(usart1_tx_rp, usart1_tx_wp, RMASK1T)) {
                        return 0;
                }
                /* write char */
                ring_write(usart1_txring,&usart1_tx_wp, RMASK1T, *str++);
                /* move on */
                len--;
        }

        RUN_USART1_TX;

        return 1;
}

uint8_t serial0_tx_PGM(const char *str) {
        uint8_t n = 0;
        char c;
        /* loop over each char in the buffer */
        while ((c = pgm_read_byte(&str[n]))) {
                /* if we would be equal to the read pointer when
     we increment the pointer, then we must discard
     the rest of the text - the TX buffer is full */
                if (!ring_writeable(usart0_tx_rp, usart0_tx_wp,RMASK0T)) {
                        return 0; /* FAILURE */
                }
                /* okay, we can write this char into the buffer */
                ring_write(usart0_txring, &usart0_tx_wp, RMASK0T, c);
                n++;
        }

        RUN_USART0_TX;

        return 1;
}

uint8_t serial1_tx_PGM(const char *str) {
        uint8_t n = 0;
        char c;
        /* loop over each char in the buffer */
        while ((c = pgm_read_byte(&str[n]))) {
                /* if we would be equal to the read pointer when
     we increment the pointer, then we must discard
     the rest of the text - the TX buffer is full */
                if (!ring_writeable(usart1_tx_rp, usart1_tx_wp, RMASK1)) {
                        return 0; /* FAILURE */
                }
                /* okay, we can write this char into the buffer */
                ring_write(usart1_txring, &usart1_tx_wp, RMASK1, c);
                n++;
        }

        RUN_USART1_TX;

        return 1;
}

/* return a character from the ring buffer */
uint8_t serial0_rx(void) {
        char c;
        /* read out the char, moving the read pointer */

        c = ring_read(usart0_rxring, &usart0_rx_rp, RMASK0R);

        if (!(ring_readable(usart0_rx_rp,usart0_rx_wp,RMASK0R))) {
                clear_flag(flag_serial,FLAG_SERIAL_U0_RX);
        }

        return c;
}

/* return a character from the ring buffer */
uint8_t serial1_rx(void) {
        char c;
        /* read out the char, moving the read pointer */

        c = ring_read(usart1_rxring, &usart1_rx_rp, RMASK1);

        if (!(ring_readable(usart1_rx_rp,usart1_rx_wp,RMASK1))) {
                clear_flag(flag_serial,FLAG_SERIAL_U1_RX);
        }

        return c;
}


uint8_t serial0_tx_hex(uint8_t c) {
        char hex[16] = "0123456789abcdef";
        serial0_tx_cout(hex[c >> 4]);
        serial0_tx_cout(hex[c & 0xf]);
        return 0;
}

uint8_t serial1_tx_hex(uint8_t c) {
        char hex[16] = "0123456789ABCDEF";
        serial1_tx_cout(hex[c >> 4]);
        serial1_tx_cout(hex[c & 0xf]);
        return 0;
}


uint8_t serial0_tx_dec(uint32_t s) {
        char a[11] = ""; /* 4294967296 */
        uint8_t n = 0;

        ultoa(s, a, 10);

        while (a[n]) {
                serial0_tx_cout(a[n]);
                n++;
        }

        return 0;

}

uint8_t serial0_tx_cr(void) {
        serial0_tx_PGM(PSTR("\r\n"));
        return 0;
}

uint8_t serial1_cr(void) {
        serial1_tx_PGM(PSTR("\r\n"));
        return 0;
}